1. Field of the Invention
The present invention relates to electronic equipment enclosures and cable interfaces for connecting the equipment enclosures with pendant cables and carrier trunk lines. More particularly, the present invention relates to a quick connect/disconnect pressure-sealed cable interface for connecting an electronic equipment enclosure to a signal-carrying trunk line via a pendant cable, wherein the equipment enclosure houses telecommunications, signaling, or other electronic equipment, including, for example, repeater and doubler cards.
2. Description of the Prior Art
It is often necessary to house telecommunications, signaling, and other electronic equipment in protective electronic equipment enclosures so that the equipment may be located where needed, often being mounted on telephone poles or within subterranean manholes. For example, ever-increasing use of wide area networks (WANs), particularly the Internet, and other telecommunication innovations has increased demand for high-speed, high-bandwidth digital telecommunications services, such as ISDN, (X)DSL, and T1, in homes and businesses. Due to signal propagation limitations, these digital services require special electronic equipment, including repeaters and doublers, to repeat signals when end users are too far from a provider""s central office.
The equipment enclosures must be connected to a carrier trunk line via a pendant cable carrying signals and other services, such as pressurized air, to and from the equipment enclosure and the electronic equipment housed therein. Currently, the pendant cable is hardwired at one end to the electronic equipment, allowed to project from the equipment enclosure, and, once the equipment enclosure is mounted, cut into the carrier trunk line. Unfortunately, such hard-wiring precludes quick and convenient connection and disconnection of the equipment enclosure for removal, maintenance, or replacement. Furthermore, because the pendant cable itself must pass directly into the equipment enclosure, leakages can develop, particularly if the cable or enclosure is roughly or improperly handled. For example, it is common practice to use the hardwired pendant cable to lower the heavy equipment enclosure into the manhole during installation. Such rough or improper handling can result in air escaping from the pressurized interior of the equipment enclosure, or can result in moisture or dust entering the equipment enclosure and damaging the electronic equipment.
Additionally, the pendant cable is typically jacketed in protective steel, making it substantially inflexible and requiring that the pendant cable connect to or exit the equipment enclosure at or near a proper angle for directly intersecting the carrier trunk line. This limitation can be difficult to accommodate in tight quarters, such as for example, subterranean manholes, where mounting locations may be dictated by size and space limitations that do not allow for the required mounting orientation.
Similar problems are encountered when installing and maintaining other electronic equipment enclosures, including signaling equipment enclosures, such as are used, for example, in controlling traffic signals.
Due to the above-identified and other limitations of the current art, a need exists for an improved mechanism for coupling a pendant cable with an electronic equipment enclosure.
The present invention solves the above-described and other problems and disadvantages to provide a distinct advance in the art of cable interfaces for electronic equipment enclosures. More particularly, the present invention provides a quick connect/disconnect pressure-sealed cable interface for connecting an electronic equipment enclosure to a signal-carrying trunk line via a pendant cable, wherein the equipment enclosure houses telecommunications, signaling, or other electronic equipment, including, for example, repeater and doubler cards.
The preferred cable interface broadly comprises a first connector half; a mounting plate; a second connector half; a free-spinning nut; a security cover; and a flexible cable extension. The first and second cable connector halves are male and female portions of a complete cable connector, and an alignment guide facilitates proper alignment of and prevents damage to the male and female connector components. A wire bundle connects at one end to the electronic equipment within the equipment enclosure, and at another end to the first cable connector half. A bottom portion of the first cable connector half is externally threaded. The mounting plate removably couples the first cable connector half to an interior or exterior surface of the equipment enclosure, preferably using threaded studs, such that the first connector half projects through the surface of the equipment enclosure. The second cable connector half provides one or more projecting tabs, each presenting a hole operable to receive a conventional padlock or combination lock. The free-spinning nut is spinably coupled with the second connector half and internally threaded in correspondence with the threaded exterior bottom portion of the first connector half, and operable when tightened thereon to secure the connector halves together.
The security cover is operable to prevent unauthorized disconnection by substantially covering the connected first and second connector halves and the free-spinning nut. The security cover provides cutouts corresponding to the projecting tabs of the bottom portion of the second connector half and through which the projecting tabs may project such that the holes therein are exposed. Thus, when the first and second connector halves are connected, and the free-spinning nut tightened, the security cover may be placed thereover and a lock placed on the projecting tab so that the security cover cannot be lowered to expose the connection without removing the lock.
The cable extension is a flexible portion of the otherwise steel-sheathed inflexible pendant cable, thereby accommodating tight radius turns up to 90xc2x0 relative to the equipment enclosure. The standard solid steel sheathing found in prior art cables is replaced in the present invention with a mesh steel sheathing over the flexible cable extension portion of the pendant cable, thereby advantageously retaining the protective qualities of steel sheathing while introducing the desired flexibility.
Thus, the cable interface of the present invention advantageously allows for quick and convenient connection and disconnection of the pendant cable from the equipment enclosure, thereby facilitating efficient removal and replacement of the equipment enclosure during, for example, maintenance or upgrade. Furthermore, the pressure-sealed interface is substantially less prone to leakage than the prior art, and can be further improved by coating or covering leak-prone areas with a sealing or potting material. Additionally, the lockable security cover advantageously provides a mechanism for preventing unauthorized disconnection. Additionally, the flexible cable extension, which uses steel mesh rather than solid steel jacketing, allows the pendant cable to affect curves up to 90xc2x0, thereby accommodating a greater variety of equipment enclosure mounting orientations relative to the carrier trunk line.
The cable interface of the present invention allows one or more pendant cables to be cut-into the trunk line substantially before or after the equipment enclosures and electronic equipment are installed This feature is particularly advantageous where cable splicing and enclosure or equipment installation is performed in phases by different technicians or crews. In order to prevent contaminants, such as moisture, debris, and dust, from entering either the cut-in pendant cable or mounted equipment enclosure, or to prevent pressurized air escaping therefrom, a two-way cap is provided operable to cap either the first or second connector half, as desired.
These and other features of the present invention are more fully described below in the section entitled DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT.